India questions 'superbug' conclusions, research ethics

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[NEW DELHI] India's health ministry has rejected the conclusions of recent research, which said the presence of a gene that makes most bacteria resistant to antibiotics in New Delhi’s water samples indicated its spread through the environment, posing a global threat.

Senior Indian scientists said the study contravened international ethical norms, as permission was required to carry biological samples out of a country that has signed the WHO’s international material transfer agreement.

A research team led by Timothy Walsh, professor at the department of infection, immunity and biochemistry, School of Medicine, Cardiff, published its findings this week (7 April) in The Lancet Infectious Diseases.

The Cardiff team analysed water samples collected between 26 September and 10 October 2010, by a television crew from UK's Channel 4 and couriered to a UK lab. The research paper said India’s commerce ministry has not listed tap and seepage water as items whose export needed clearance.

The Cardiff team found the resistance conferring gene, 'New Delhi metallo-beta-lactamase' (NDM-1) in two out of 50 drinking water samples, and 51 out of 171 seepage samples. Control water samples from Cardiff did not contain bacteria with the gene.

The health ministry's official statement this week (7 April) said the environmental presence of NDM-1 gene carrying bacteria "is not a significant finding since there is no clinical or epidemiological linkage of this finding in the study area as given in the publication. The fact that patients respond well to medical and post-surgical antibiotic treatment indicates that NDM-1 is not a significant problem in the country".

The ministry cited a study by the Sir Ganga Ram Hospital, New Delhi, over the past two years, which showed that Escherichia coli bacteria isolated from stool samples of randomly-selected pregnant women, from the same area, did not indicate presence of the NDM-1 gene.

"The [Lancet Infectious Diseases] publication itself mentions that the NDM-1 gene is not a stable character in most of the isolates, indicating that at any time it can revert back to a sensitive state," the statement said.

The ministry said chlorination of Delhi’s drinking water "inactivates sensitive and drug-resistant bacteria alike".

Vishwa Mohan Katoch, director-general of the Indian Council of Medical Research, told the media yesterday (7 April) that the manner in which samples were carried from India to the UK "does not point to a good scientific motive. It is illegal".

Katoch observed that there were thousands of genes causing multi-bacterial resistance, in many parts of the world. "To keep on pressing India as a hotbed of such superbugs is unfair and its motive is questionable," the daily Times of India quoted him as saying.

Sarman Singh, professor and head, division of clinical microbiology, All India Institute of Medical Sciences, New Delhi, told SciDev.Net that the research paper was "scientifically sound" and added "new knowledge to our understanding".

“However, the study deserves strict criticism on the ground of ethics and international affairs,” Singh said.

Singh added the Indian government too must introspect as Indian scientists are often denied permission to develop foreign collaborations. “If foreign nationals take any biological material without proper permission, [the] government of India cannot do anything, but if a sincere research collaboration is planned such studies face Herculean task to get clearances.”